Optical information processing, as a novel technology which has been developed in recent years, due to its high processing speed, large information flow and the like, especially excellent interference resistance against light waves and capability of transferring and processing loaded information concurrently, has great application value in the field of information, national defense and the like. A spatial light modulator is a device for modulating spatial distribution of the light waves, and specifically a device for spatially and temporally transforming or modulating one-dimensional or two-dimensional distribution of certain properties (such as amplitude, phase, polarization and frequency) of the light waves thus to write information loaded by a source signal into incident light. At present, the technologies to realize a spatial light modulator mainly include electro absorption modulation, electro-optical modulation, liquid crystal, MEMS and the like. The low-speed operation of the liquid crystal modulation and MEMS modulation can not meet the application of high-speed modulation; the electro absorption modulation has high cost as it is generally based on gallium arsenide quantum well material, the process is very complicated since the entire structure often requires epitaxy of dozens of layers of heterogeneous material, and the uniformity of a plurality of layers of material further limits the size of the array as well as the depth of modulation; and as the electro-optical modulation is generally based on nonlinear crystal material or polymers, this results in large device volume and high drive voltage.